Connection for a nonmetallic foundation pile

ABSTRACT

The invention relates to a pile or foundation member particularly adapted for use in offshore or similar applications, wherein a hostile environment or a severe corrosion problem is a pertinent factor. The pile comprises an elongated member formed essentially of a series of reinforced concrete pile sections. A metallic cap carried at each pile section end is adapted to engage and be fixed to a corresponding cap on the next succeeding pile end whereby to define a rigid interface connection between the two. The metal joint thus formed between the concrete sections is then isolated from its surroundings by means of an encapsulating or enclosing barrier formed on the pile whereby to be protected from the environment.

United States Patent 1 Pogonowski et al.

[111 3,748,863 [451 July 31,1973

[ CONNECTION FOR A NONMETALLIC FOUNDATION PILE [73] Assignee: Texaco Inc., New York, NY.

[22] Filed: Jan. 19, 1972 [21] Appl. No.: 218,877

[52] US. Cl 61/53, 61/56, 285/294,

285/331, 285/404 [51] Int. Cl. E0211 5/22, F16] 25/00 [58] Field of Search 61/53, 56, 54;

[56] References Cited UNITED STATES PATENTS France 285/294 Germany 61/54 Primary Examiner-Jacob Shapiro AttorneyThomas H. Whaley et al.

[57] ABSTRACT The invention relates to a pile or foundation member particularly adapted for use in offshore or similar applications, wherein a hostile environment or a severe corrosion problem is a pertinent factor. The pile comprises an elongated member formed essentially of a series of reinforced concrete pile sections. A metallic cap carried at each pile section end is adapted to engage and be fixed to a corresponding cap on the next succeeding pile end whereby to define a rigid interface connection between the two. The metal joint thus formed between the concrete sections is then isolated from its surroundings by means of an encapsulating or enclosing barrier formed on the pile whereby to be protected from the environment.

3 Claims, 3 Drawing Figures CONNECTION FOR A NONMETALLIC FOUNDATION PILE BACKGROUND OF THE INVENTION The use of foundation piles in certain offshore as well as onshore structures, is widespread for fixedly positioning such structures. Normally, the pile is made of such a material as to effectively support the structure preferably under compressive loading conditions. In the instance of offshore units for piers, drilling platforms and the like, the pile is of course relatively elongated and extends between the ocean floor and surface thereof, being embedded at its lower end into the substratum.

In the instance of metal piles, the necessary pile length is obtained merely by welding sequential sections one to the other as the pile is driven into the substratum. In situations where the pile is used in an environment that would be hostile or corrosive to metal, another form of support means must be utilized.

One of the more versatile and least expensive forms of piling, particularly for foundation use, resides in a concrete member either reinforced or otherwise. The latter is usually buried to a sufficient depth, and provided in adequate numbers to support an overhead structure. The pile length and depth of embedment are of course functions of the soil composition and condition at the pile site.

In the instance of concrete piles, it is often desired that reinforced pile lengths be connected one to the other for elongating the pile as it is driven into the substratum. One of the most practical forms of connection for this purpose resides in a means whereby the discrete pile lengths can be rapidly and firmly secured by cooperating metallic collars carried at the ends of each length.

Toward overcoming the detrimental effect on metallic connections in a concrete pile, the invention as presently described provides an arrangement whereby respective pile sections can be rapidly and conveniently connected as well as protected. The interface connection is achieved through the use of one or more circumferentially placed keys which interconnect a pair of corresponding pile segment caps, in such a manner as to fixedly secure the respective segments in interlocked relationship.

The entire joint or connection formed at the interface is thereafter enclosed or encapsulated within a moisture and vapor resistant barrier. Thus, the entire metallic connection is in effect embedded into the protective coating and is never exposed to the surrounding corrosive or hostile atmosphere.

DESCRIPTION OF THE DRAWINGS FIG. I of the drawings represents an environmental view of the instant foundation pile, a portion of the view being shown in vertical cross section. FIG. 2 is a segmentary view on an enlarged scale and in cross section, showing the connection between various pile sections subsequent to being completed. FIG. 3 is an enlarged cross sectional view illustrating the various pile sections immediately prior to their being connected during the procedure of lowering the upper one onto the corresponding surface of the lower one.

Referring to FIG. I, the instant foundation pile is illustrated for the purpose of disclosing the features thereof, as constituting a number of such piles spaced apart and embedded in a body of water for supporting a deck, a platform, or similar structure above the waters surface. The respective piles 10 are disposed in a hostile element, a portion of the latter being contributed by the corrosive atmosphere of the moist, salt air generally prevalent to varying degrees in such installations. Piles 10 as mentioned, are capable of supporting a deck or platform a distance from the shore. In a similar manner they could be used for a shore installation or for providing the foundation for a pier extending from the shore, out into the body of water.

In either instance the function of the piles as a whole is to elevate a weighty structure or body a slight distance beyond the waters surface. The respective piles as shown, are embedded substantially vertically in the substratum. Normally this is achieved by driving the pile in a manner to force its entry into the substratum to a point where no further downward progress can be realized. During this step the pile is sequentially elongated by the addition to the upper end thereof of short pile sections or segments 12. Thus, the final pile is comprised of a plurality of such end connected sections the last of which protrudes upward beyond the waters surface.

The instant pile 10 arrangement comprises a hollow or cylindrical structure. This however is not to be construed as a limitation since such structures can as well be fabricated solidly of concrete or of a similar corrosion resistant material. Further, and as known in the art, to improve the strength characteristics of a concrete member the latter can be provided with a reinforcing element as prestressed metal bands, rods, or the like disposed within the pile walls. It is appreciated further that while the instant pile is shown as being circular in cross section, such is not a limitation since the desired support function can be achieved regardless of the sectional geometric configuration of the pile.

Referring to FIG. 2, the ultimately connected pile 10 is shown with upper pile section 12 connected to lower pile section 13. This connection can be either above or below the water level, being amply protected in either instance. In the illustrated arrangement the pile connection means 14 comprises correspondingly aligned members which are joined in rigid interlocked position by means of a plurality of peripherally spaced keys or similar devices. The area immediately surrounding metallic connection 14 is completely embedded within an envelope of a sealing material 16, which functions to preclude entrance of the herein mentioned hostile environment which could be either the corrosive salt water atmosphere or other corrosive medium either liquid or vaporous.

Referring to FIG. 3, upper pile section I2 is shown as carrying an alignment guide means 17 on the pile inner surface. Said guide means comprises, for the present pile configuration, a circular shaped, cylindrical member having an outer diameter slightly less than the diameter of the internal passage formed through the lower pile section 13. Said alignment guide 17 is provided with a taper at the lower end to facilitate the lowering of upper pile section 12 in a manner to properly register the guide 17 within the central passage of the lower pile section 13. In such a position, the joint connection 14 is properly aligned and need only be rotatably adjusted to achieve the correct interlocking arrangement.

Lower pile section 13 comprises as previously noted, a wall 18 which is normally formed of concrete having a sufficient width to withstand the compressive force applied thereto by the supported deck or structure. A cap 19 is fixed to end face 21 of pile section 13, and comprises a generally circular member which is preferably continuous, although it can be divided into discrete, arcuate segments. Cap member 19 comprises a base 22 from which a pair of parallel side walls 23 and 24 extend, thereby defining an annular space therebetween which forms a peripheral groove 25 at the pile end face.

Cap 19 is fastened into the end face of the pile wall by one or more annular, extending flanges 26 and 27 which depend from the base 22 opposite side. Alternatively, the cap can be anchored by a plurality of support bars which, in a similar manner, depend from the cap and are completely embedded in the concrete wall. Each of said spaced apart side walls 23 and 24 is provided with seating surfaces 230 and 24a along the upper side thereof which are adapted to mate with a contact seat and corresponding cap formed on upper pile section 12.

Pile section 12 comprises an element constructed similarly to the lower pile section 13, the two members being substantially identical. However, said upper pile section 12 is provided with a cap 30 at the lower face thereof which comprises a peripheral body 31 from which a tongue or rim 32 depends. Said rim 32 is adapted to slidably engage groove 25 formed in the corresponding lower positioned cap 19.

Upper cap 30 can be formed of a plurality of discrete or peripherally separated rim segments so long as the latter corresponds with similarly arranged portions of the grooved cap 19. As shown, both upper and lower caps are provided with a plurality of peripherally spaced openings 33 which are aligned with similar openings 34 in cap 19 to receive a locking member 36 such as a key, a bolt or similar device adapted to mutually engage the respective members in their locked position as well as to fixedly hold them in said position.

In the instant arrangement, key 36 is provided with a substantially round body having a tapered lower end to facilitate being forcefully driven into the aligned transverse openings. A head 37 formed on the outer end of the key 36, permits the latter to be driven into the opening to holding position. As shown in FIG. 2, in the fully assembled position, key 36 extends through the outer surface of both sides of the cap. Further, fastening means can be applied to the inner end of the key such as a cotter pin whereby to hold the key in place. However, as will be mentioned with the insertion of the embedding material into the area immediately adjacent the connection 14, such further fastening of the key is not essential.

Upper pile section 12 is provided with a circumferential belt 41 which is operably carried on the pile outer surface in a manner to permit the belt to be slid downwardly such that the upper and lower pile sections are in mutual engagement with the belt. Belt 41 can assume a number of embodiments including a relatively thin metallic band, or a flexible member adapted to provide a tight fit with both upper and lower pile sections when the belt is lowered into place.

ln either event and as shown in FIG. 2, belt 41 is positioned to form a peripheral cover about connection 14. The fluidized embedding material can be inserted through the belt by means of inlet 42, together with a conduit 43 attached thereto. The latter extends to a source of the embedding material usually heated or otherwise maintained in a liquefied state.

Similarly, the inner side of connection 14 is provided with a fluidized embedding material which is introduced by way of transverse openings 44 in the caps 19 and 30. The material forming the vapor resistant barrier can be any one of several such materials adapted to being fluidized and subsequently hardened. For example, one such material comprises an alumina cement grout which can be inserted in liquid condition and set within 6 to 8 hours. Other more quickly setting materials apply equally as well. A bituminous based slurry can also be utilized as the embedding substance, which slurry is applied hot, and will quickly harden particularly at low temperatures.

To form the fluid holding seal about the connector annular passage, said alignment guide 17 is provided with a layer 46 of a resilient material adapted to yield sufficiently when slid into place adjacent to the connection 14, as to form upper and lower peripheral seals thereabout. It is understood that to facilitate the injection of the fluidized hardenable material, the annulus defined about the connection means 14 can be communicated with the atmosphere either through the respective outer band 41, the inner seal ring 46 or otherwise. In either instance a substantially solid band of fluidized material can be injected about the metallic connection and thence through passages 44, and be subsequently hardened to form a rigid embedding barrier.

In the process of forming the instant connection between the respective pile segments, lower pile 13 normally is driven a desired distance into the substratum beneath a body of water. With the lower portion fixedly positioned, upper pile section 12 is suspended in vertical alignment and lowered onto the end of said initially positioned pile section 13. During the lowering proeedure, proper alignment is assured between the mating pile sections by the action of alignment guide 17 which initially engages the walls of the lower pile 13 center passage.

Thereafter, pile section 12 can be further dropped onto the lower section in a manner that the respective cap members 19 and 30 fall into proper alignment. This latter step is achieved such that the cross openings 33 and 34 are in proper horizontal alignment. The upper and lower pile sections are provided with further guide means such as shown in FIG. 1 wherein an indented portion 48 is formed in the peripheral flange, and which engages an upwardly extending correspondingly shaped tang 49. Thus, with pile sections 12 and 13 in substantial alignment from a vertical standpoint, rotating of upper section 12 will cause tang 49 to engage groove 48 to further accurately position the respective transverse key openings.

Preferably connection caps 19 and 30 are mutually fabricated in such manner that the respective cross openings 33 and 34 are aligned when the connection is in the engaged condition. Thereafter, although the respective sections are subsequently separated for inser tion onto a pile surface they will nonetheless be accurately alignable such as to permit key 36 to be driven into the cross openings usually with the aid of power tools or the like.

With the present arrangement, subsequent to the hardening of the embedding material about connection 14, the pile is in condition for use. It can then be further driven into the substratum as to dispose the connection beneath the body of water, or beyond the waters surface. In the latter instance it may be at a future time necessary to replace the entire pile section due to the effects of the environment such as the salt water atmosphere or eroding of the pile wall by waves and the like such that removal of the pile upper section is warranted.

Other modifications and variations of the invention as hereinbefore set forth may be made without departing from the spirit and scope thereof, and therefore, only such limitations should be imposed as are indicated in the appended claims.

We claim:

1. A longitudinally extendable foundation pile for use in the presence of an environment hostile to metallic structures, and adapted to be embedded into a substratum which comprises;

a nonmetallic pile element formed of a plurality of longitudinally positioned elongated pile sections having oppositely disposed end faces and being connected one to the other at said end faces,

an interface connector disposed intermediate adjacent end faces of said respective pile sections and including,

a pair of detachably interlocked connector members,

at least one locking key mutually engaging said pair of connector members to maintain them in rigid interlocked relationship, and

means forming an enveloping barrier about said foundation pile whereby to enclose said interface connector from exposure to the surrounding hostile environment,

and alignment guide means carried at the end of one of said pile sections and adapted to slidably engage a surface of an adjacent pile segment, whereby to guide the respective sections together when the latter are brought into alignment whereby to engage said interface connector members.

2. In an apparatus as defined in claim 1, including; a confining belt operably carried on a pile section and being slidably adjustable to circumferentially enclose said interface connector subsequent to the latter becoming interlocked and prior to introducing said fluid tight barrier.

3. In an apparatus as defined in claim 2, wherein a portion of said fluid tight barrier is disposed internally of said pile, and adjacent to said interface connector. 

1. A longitudinally extendable foundation pile for use in the presence of an environment hostile to metallic structures, and adapted to be embedded into a substratum which comprises; a nonmetallic pile element formed of a plurality of longitudinally positioned elongated pile sections having oPpositely disposed end faces and being connected one to the other at said end faces, an interface connector disposed intermediate adjacent end faces of said respective pile sections and including, a pair of detachably interlocked connector members, at least one locking key mutually engaging said pair of connector members to maintain them in rigid interlocked relationship, and means forming an enveloping barrier about said foundation pile whereby to enclose said interface connector from exposure to the surrounding hostile environment, and alignment guide means carried at the end of one of said pile sections and adapted to slidably engage a surface of an adjacent pile segment, whereby to guide the respective sections together when the latter are brought into alignment whereby to engage said interface connector members.
 2. In an apparatus as defined in claim 1, including; a confining belt operably carried on a pile section and being slidably adjustable to circumferentially enclose said interface connector subsequent to the latter becoming interlocked and prior to introducing said fluid tight barrier.
 3. In an apparatus as defined in claim 2, wherein a portion of said fluid tight barrier is disposed internally of said pile, and adjacent to said interface connector. 